Recherche avancée

Sur d’autres sites (6533)

• Privacy in Business : What Is It and Why Is It Important ?

  13 juillet 2022, par Erin — Privacy

  Privacy concerns loom large among consumers. Yet, businesses remain reluctant to change the old ways of doing things until they become an operational nuisance. 

  More and more businesses are slowly starting to feel the pressure to incorporate privacy best practices. But what exactly does privacy mean in business ? And why is it important for businesses to protect users’ privacy ? 

  In this blog, we’ll answer all of these questions and more. 

  What is Privacy in Business ?

  In the corporate world, privacy stands for the business decision to use collected consumer data in a safe, secure and compliant way. 

  Companies with a privacy-centred culture : 

  • Get explicit user consent to tracking, opt-ins and data sharing 
  • Collect strictly necessary data in compliance with regulations 
  • Ask for permissions to collect, process and store sensitive data 
  • Provide transparent explanations about data operationalisation and usage 
  • Have mechanisms for data collection opt-outs and data removal requests 
  • Implement security controls for storing collected data and limit access permissions to it 

  In other words : They treat consumers’ data with utmost integrity and security – and provide reassurances of ethical data usage. 

  What Are the Ethical Business Issues Related to Privacy ?

  Consumer data analytics has been around for decades. But digital technologies – ubiquitous connectivity, social media networks, data science and machine learning – increased the magnitude and sophistication of customer profiling.

  Big Tech companies like Google and Facebook, among others, capture millions of data points about users. These include general demographics data like “age” or “gender”, as well as more granular insights such as “income”, “past browsing history” or “recently visited geo-locations”. 

  When combined, such personally identifiable information (PII) can be used to approximate the user’s exact address, frequently purchased goods, political beliefs or past medical conditions. Then such information is shared with third parties such as advertisers. 

  That’s when ethical issues arise. 

  The Cambridge Analytica data scandal is a prime example of consumer data that was unethically exploited. 

  Over the years, Google also faced a series of regulatory issues surrounding consumer privacy breaches :

  • In 2021, a Google Chrome browser update put some 2.6 billion users at risk of “surveillance, manipulation and abuse” by providing third parties with data on device usage. 
  • The same year, Google was taken to court for failing to provide full disclosures on tracking performed in Google Chrome incognito mode. A $5 billion lawsuit is still pending.
  • As of 2022, Google Analytics 4 is considered GDPR non-compliant and was branded “illegal” by several European countries. 

  If you are curious, learn more about Google Analytics privacy issues. 

  The bigger issue ? Big Tech companies make the businesses that use their technologies (unknowingly) complicit in consumer data violations.

  In 2022, the Belgian data regulator found the official IAB Europe framework for user consent gathering in breach of GDPR. The framework was used by all major AdTech platforms to issue pop-ups for user consent to tracking. Now ad platforms must delete all data gathered through these. Biggest advertisers such as Procter & Gamble, Unilever, IBM and Mastercard among others, also received a notice about data removal and a regulatory warning on further repercussions if they fail to comply. 

  Big Tech firms have given brands unprecedented access to granular consumer data. Unrestricted access, however, also opened the door to data abuse and unethical use. 

  Examples of Unethical Data Usage by Businesses 

  • Data hoarding means excessively harvesting all available consumer data because a possibility to do so exists, often using murky consent mechanisms. Yet, 85% of collected Big Data is either dark or redundant, obsolete or trivial (ROT).
  • Invasive personalisation based on sensitive user information (or second-guesses), like a recent US marketing campaign, congratulating women on pregnancy (even if they weren’t expecting). Overall, 75% of consumers find most forms of personalisation somewhat creepy. 22% also said they’d leave for another brand due to creepy experiences.
  • Hyper-targeted advertising campaigns based on data consumers would prefer not to share. A recent investigation found that advertising platforms often assign sensitive labels to users (as part of their ad profiles), indicative of their religion, mental issues, history with abuse and so on. This allows advertisers to target such consumers with dubious ads. 

  Ultimately, excessive data collection, paired with poor data protection in business settings, results in major data breaches and costly damage control. Given that cyber attacks are on the rise, every business is vulnerable. 

  Why Should a Business Be Concerned About Protecting the Privacy of Its Customers ?

  Businesses must prioritise customer privacy because that’s what is expected of them. Globally, 89% of consumers say they care about their privacy. 

  As frequent stories about unethical data usage, excessive tracking and data breaches surface online, even more grow more concerned about protecting their data. Many publicly urge companies to take action. Others curtail their relationships with brands privately. 

  

  On average, 45% of consumers feel uncomfortable about sharing personal data. According to KPMG, 78% of American consumers have fears about the amount of data being collected. 40% of them also don’t trust companies to use their data ethically. Among Europeans, 41% are unwilling to share any personal data with businesses. 

  Because the demand for online privacy is rising, progressive companies now treat privacy as a competitive advantage. 

  For example, the encrypted messaging app Signal gained over 42 million active users in a year because it offers better data security and privacy protection. 

  ProtonMail, a privacy-centred email client, also amassed a 50 million user base in several years thanks to a “fundamentally stronger definition of privacy”.

  The growth of privacy-mindful businesses speaks volumes. And even more good things happen to privacy-mindful businesses : 

  • Higher consumer trust and loyalty 
  • Improved attractiveness to investors
  • Less complex compliance
  • Minimum cybersecurity exposure 
  • Better agility and innovation

  It’s time to start pursuing them ! Learn how to embed privacy and security into your operations.

• Apostrophe issue with FFmpeg

  1er mars 2024, par Rohan Molinillo

  I'm working on a company's project which is vue.js.
There are also code parts in php.
It uses FFmpeg to create a video from multiple videos.
On each video, there is a text type subtitle.
Each text is retrieved from a .txt file
But I have a problem with apostrophes.

  


  If in the subtitle is stored like this ( I'm here ) in the txt file, on the video there will be written ( Im ).
The apostrophe is removed and the rest of the text too ( here ) will not be displayed.

  


  I'm new to php and ffmpeg, I've been on this problem for almost 3 weeks.

  


  I share the php code with you.

  


  <?php

declare(strict_types=1);

array_shift($argv); // remove script name in $argv[0]

$parameters = array_reduce($argv, function ($carry, $arg) {
    $tokens = explode('=', $arg);
    $carry[$tokens[0]] = $tokens[1];
    return $carry;
}, []);

$projectPath = $parameters['projectPath'];
$musicPath = $parameters['musicPath'];

$fontPath = getcwd() . "/public/fonts/cobol/Cobol-Bold.ttf";
$logoPath = getcwd() . "/public/images/saintex.jpg";
$carnetLogoPath = getcwd() . "/public/images/CarnetTitre.jpg";

// Adding descriptions for each clip and fade in and fade out filters
$clipsToDescribe =  glob("$projectPath/*.webm");
$clipFrameRate = (int) shell_exec("cd $projectPath && ffprobe -v error -select_streams v -of default=noprint_wrappers=1:nokey=1 -show_entries stream=r_frame_rate $clipsToDescribe[0]");
$clipFrameRate = $clipFrameRate > 60 ? 30 : $clipFrameRate;

foreach ($clipsToDescribe as $key => $clipToDescribe) {
    $clipIndex = $key + 1;
    $clipFrames = (int) shell_exec("cd $projectPath && ffprobe -v error -select_streams v:0 -count_packets -show_entries stream=nb_read_packets -of csv=p=0 $clipToDescribe");
    $clipDuration = (float) ($clipFrames / $clipFrameRate) - 0.5;
    file_put_contents("$projectPath/clip{$clipIndex}_desc.txt", addslashes($parameters["clip{$clipIndex}_desc"]));
    shell_exec("cd $projectPath && ffmpeg -i $clipToDescribe -vf 'drawtext=fontfile=$fontPath: textfile=clip{$clipIndex}_desc.txt: fontcolor=white: fontsize=46: box=1: boxcolor=black@0.5: boxborderw=5: x=(w-text_w)/2: y=(h-text_h-50): fix_bounds=true, fade=t=in:st=0:d=0.3,fade=t=out:st=$clipDuration:d=0.3' -b:v 3000K -b:a 192K clip{$clipIndex}.webm");
}
array_map('unlink', glob("$projectPath/*desc.txt"));

shell_exec("cd $projectPath && ffmpeg -t 2 -f lavfi -i color=c=black:s=1280x720 -r 30 blank.webm");
shell_exec("cd $projectPath && ffmpeg -i blank.webm -i $carnetLogoPath -filter_complex '[0:v][1:v] overlay=(main_w/2)-(overlay_w/2):(main_h/2)-(overlay_h/2)' -pix_fmt yuv420p -c:a copy logo.webm");



$workshop = $parameters["workshop_type"];
$title = $parameters["title"];
shell_exec("cd $projectPath && ffmpeg -f lavfi -i color=size=1280x720:duration=3:rate=30:color=black -vf 'drawtext=text=$workshop:fontfile=$fontPath:fontcolor=white:fontsize=46:x=(w-text_w)/2:y=(h-text_h)/2, drawtext=text=$title:fontfile=$fontPath:fontcolor=white:fontsize=46:x=(w-text_w)/2:y=((h-text_h)/2)+lh+5' opening.webm");
unlink("$projectPath/blank.webm");

$videosFile = "file 'logo.webm'\n";
$videosFile .= "file 'opening.webm'\n";{
    file_put_contents("$projectPath/project_desc.txt", $parameters["project_desc"]);
    shell_exec("cd $projectPath && ffmpeg -f lavfi -i color=size=1280x720:duration=3:rate=30:color=black -vf 'drawtext=fontfile=$fontPath:fontsize=46:fontcolor=white:x=(w-text_w)/2:y=(h-text_h)/2:textfile=project_desc.txt' project_desc.webm");
    unlink("$projectPath/project_desc.txt");
    $videosFile .= "file 'project_desc.webm'\n";
} 
if(array_key_exists("participants", $parameters)) {
    file_put_contents("$projectPath/participants.txt", "Participants :\n" . $parameters["participants"]);
    shell_exec("cd $projectPath && ffmpeg -f lavfi -i color=size=1280x720:duration=2:rate=30:color=black -vf 'drawtext=fontfile=$fontPath:fontsize=46:fontcolor=white:x=(w-text_w)/2:y=(h-text_h)/2:textfile=participants.txt' participants.webm");
    unlink("$projectPath/participants.txt");
}

$videos =  glob("$projectPath/clip*.webm");
foreach($videos as $video) {
    if($video != "originalVideos") {
        $videosFile .= "file ". "'{$video}'\n";
    }
} 
if(array_key_exists("participants", $parameters)) {
    $videosFile .= "file '$projectPath/participants.webm'";
}
array_map('unlink', glob("$projectPath/*webm.txt"));
file_put_contents("$projectPath/videosFile.txt", $videosFile);
if($musicPath == "/_musics/") {
    echo(shell_exec("cd $projectPath && ffmpeg -f concat -safe 0 -i videosFile.txt -b:v 10000K -crf 20 -b:a 192K output.webm"));
} else {
    echo(shell_exec("cd $projectPath && ffmpeg -f concat -safe 0 -i videosFile.txt -b:v 10000K -crf 20 -b:a 192K assembled.webm && ffmpeg -i assembled.webm -i ../..$musicPath -filter_complex ' [1:0] apad ' -shortest -y -b:v 3000K -b:a 192K output.webm"));
}


  


  I tried many things but each time there were errors.
I think I didn't implement the code properly.

  


  I share you the error

  


          [09:21:02] RECEIVED EVENT: videoRequest
{ Error: Command failed: php ./public/src/generate.php projectPath='/home/rohan/Documents/dodoc2/_projects/its-a-test' musicPath='/_musics/classic.mp3' clip1_name='' clip2_name='' clip3_name='' clip4_name='' clip5_name='' clip1_desc='It's a first test' clip2_desc='It's a second test' clip3_desc='It's a third test' clip4_desc='It's a fourth' clip5_desc='It's a last test' project_desc='' workshop_type='Atelier Robotique' title='It's a test' participants='Molinillo Rohan
'
PHP Warning:  Undefined array key 1 in /home/rohan/carnet-numerique/public/src/generate.php on line 9
PHP Warning:  Undefined array key 1 in /home/rohan/carnet-numerique/public/src/generate.php on line 9
PHP Warning:  Undefined array key 1 in /home/rohan/carnet-numerique/public/src/generate.php on line 9
PHP Warning:  Undefined array key 1 in /home/rohan/carnet-numerique/public/src/generate.php on line 9
PHP Warning:  Undefined array key 1 in /home/rohan/carnet-numerique/public/src/generate.php on line 9
PHP Warning:  Undefined array key 1 in /home/rohan/carnet-numerique/public/src/generate.php on line 9
ffmpeg version 5.1.1-1ubuntu2.1 Copyright (c) 2000-2022 the FFmpeg developers
  built with gcc 12 (Ubuntu 12.2.0-3ubuntu1)
  configuration: --prefix=/usr --extra-version=1ubuntu2.1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl --disable-stripping --enable-gnutls --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libcodec2 --enable-libdav1d --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libglslang --enable-libgme --enable-libgsm --enable-libjack --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librabbitmq --enable-librist --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libsrt --enable-libssh --enable-libsvtav1 --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzimg --enable-libzmq --enable-libzvbi --enable-lv2 --enable-omx --enable-openal --enable-opencl --enable-opengl --enable-sdl2 --disable-sndio --enable-pocketsphinx --enable-librsvg --enable-libmfx --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libx264 --enable-libplacebo --enable-shared
  libavutil      57. 28.100 / 57. 28.100
  libavcodec     59. 37.100 / 59. 37.100
  libavformat    59. 27.100 / 59. 27.100
  libavdevice    59.  7.100 / 59.  7.100
  libavfilter     8. 44.100 /  8. 44.100
  libswscale      6.  7.100 /  6.  7.100
  libswresample   4.  7.100 /  4.  7.100
  libpostproc    56.  6.100 / 56.  6.100
Input #0, matroska,webm, from '/home/rohan/Documents/dodoc2/_projects/its-a-test/video-20230404-091933-682.webm':
  Metadata:
    encoder         : QTmuxingAppLibWebM-0.0.1
  Duration: N/A, start: -0.001000, bitrate: N/A
  Stream #0:0(eng): Video: vp8, yuv420p(progressive), 1280x720, SAR 1:1 DAR 16:9, 1k tbr, 1k tbn (default)
  Stream #0:1(eng): Audio: opus, 48000 Hz, stereo, fltp (default)
Stream mapping:
  Stream #0:0 -> #0:0 (vp8 (native) -> vp9 (libvpx-vp9))
  Stream #0:1 -> #0:1 (opus (native) -> opus (libopus))
Press [q] to stop, [?] for help
[libvpx-vp9 @ 0x55952c183000] v1.12.0
Output #0, webm, to 'clip1.webm':
  Metadata:
    encoder         : Lavf59.27.100
  Stream #0:0(eng): Video: vp9, yuv420p(tv, bt470bg/unknown/unknown, progressive), 1280x720 [SAR 1:1 DAR 16:9], q=2-31, 3000 kb/s, 1k fps, 1k tbn (default)
    Metadata:
      encoder         : Lavc59.37.100 libvpx-vp9
    Side data:
      cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: N/A
  Stream #0:1(eng): Audio: opus, 48000 Hz, stereo, flt, 192 kb/s (default)
    Metadata:
      encoder         : Lavc59.37.100 libopus
frame=  229 fps= 11 q=12.0 Lsize=    2786kB time=00:00:07.52 bitrate=3034.7kbits/s speed=0.377x    
video:2601kB audio:181kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.175036%
PHP Warning:  Undefined array key "clip2_desc" in /home/rohan/carnet-numerique/public/src/generate.php on line 29
PHP Fatal error:  Uncaught TypeError: addslashes(): Argument #1 ($string) must be of type string, null given in /home/rohan/carnet-numerique/public/src/generate.php:29
Stack trace:
#0 /home/rohan/carnet-numerique/public/src/generate.php(29): addslashes()
#1 {main}
  thrown in /home/rohan/carnet-numerique/public/src/generate.php on line 29

    at ChildProcess.exithandler (child_process.js:275:12)
    at emitTwo (events.js:126:13)
    at ChildProcess.emit (events.js:214:7)
    at maybeClose (internal/child_process.js:925:16)
    at Socket.stream.socket.on (internal/child_process.js:346:11)
    at emitOne (events.js:116:13)
    at Socket.emit (events.js:211:7)
    at Pipe._handle.close [as _onclose] (net.js:554:12)
  killed: false,
  code: 255,
  signal: null,
  cmd: 'php ./public/src/generate.php projectPath=\'/home/rohan/Documents/dodoc2/_projects/its-a-test\' musicPath=\'/_musics/classic.mp3\' clip1_name=\'\' clip2_name=\'\' clip3_name=\'\' clip4_name=\'\' clip5_name=\'\' clip1_desc=\'It\'s a first test\' clip2_desc=\'It\'s a second test\' clip3_desc=\'It\'s a third test\' clip4_desc=\'It\'s a fourth\' clip5_desc=\'It\'s a last test\' project_desc=\'\' workshop_type=\'Atelier Robotique\' title=\'It\'s a test\' participants=\'Molinillo Rohan\n\'' }


  


• Understanding The Dreamcast GD-ROM Layout

  24 mars 2022, par Multimedia Mike — Sega Dreamcast

  I’m finally completing something I set out to comprehend over a decade ago. I wanted to understand how data is actually laid out on a Sega Dreamcast GD-ROM drive. I’m trying to remember why I even still care. There was something about how I wanted to make sure the contents of a set of Dreamcast demo discs was archived for study.

  
  
  

  I eventually figured it out. Read on, if you are interested in the technical details. Or, if you would like to examine the fruits of this effort, check out the Dreamcast demo discs that I took apart and uploaded to the Internet Archive.

  If you care to read some geeky technical details of some of the artifacts on these sampler discs, check out this followup post on Dreamcast Finds.

  Motivation
  Why do I still care about this ? Well, see the original charter of this blog above. It’s mostly about studying multimedia formats, as well as the general operation of games and their non-multimedia data formats. It’s also something that has nagged at me ever since I extracted a bunch of Dreamcast discs years ago and tried to understand why the tracks were arranged the way they were, and how I could systematically split the files out of the filesystem. This turns out not to be as easy as it might sound, even if you can get past the obstacle of getting at the raw data.
  

  CD/CD-ROM Refresher
  As I laid out in my Grand Unified Theory of Compact Disc, every compact disc can be viewed conceptually as a string of sectors, where each sector is 2352 bytes long. The difference among the various CD types (audio CDs, various CD-ROM types) boils down to the format of contents of the 2352-byte sectors. For an audio CD, every sector’s 2352 bytes represents 1/75 of a second of CD-quality audio samples.

  Meanwhile, there are various sector layouts for different CD-ROM modes, useful for storing computer data. This post is most interested in “mode 1/form 1”, which uses 2048 of the 2352 bytes for data, while using the remaining bytes for error detection and correction codes. A filesystem (usually ISO-9660) is overlaid on these 2048-byte sectors in order to create data structures for organizing strings of sectors into files.

  A CD has between 1 and 99 tracks. A pure CD-ROM will have a single data track. Pure audio CDs tend to have numerous audio tracks, usually 1 per song. Mixed CDs are common. For software, this usually manifests as the first track being data and containing an ISO-9660 filesystem, followed by a series of audio tracks, sometimes for in-game music. For audio CDs, there is occasionally a data track at the end of the disc with some extra media types.

  GD-ROM Refresher
  The Dreamcast used optical discs called GD-ROMs, where the GD stands for “gigadisc”. These discs were designed to hold about 1 gigabyte of data, vs. the usual 650-700MB offered by standard CD solutions, while using the same laser unit as is used for CDs. I’m not sure how it achieved this exactly. I always assumed it was some sort of “double density” sector scheme. According to Wikipedia, the drive read the disc at a slower rate which allowed it to read more data (presumably the “pits” vs. “lands” which comprise the surface of an optical disc). This might be equivalent to my theory.

  The GD-ROM discs cannot be read in a standard optical drive. It is necessary to get custom software onto the Dreamcast which will ask the optical hardware to extract the sectors and exfiltrate them off of the unit somehow. There are numerous methods for this. Alternatively, just find rips that are increasingly plentiful around the internet. However, just because you might be able to find the data for a given disc does not mean that you can easily explore the contents.

  Typical Layout Patterns
  Going back to my study of the GD-ROM track layouts, 2 clear patterns emerge :

  All of the game data is packed into track 3 :

  
  
  

  Track 3 has data, the last track has data, and the tracks in between contain standard CD audio :

  
  
  

  Also, the disc is always, always 100% utilized.

  Track 1 always contains an ISO-9660 filesystem and can be read by any standard CD-ROM drive. And it usually has nothing interesting. Track 3 also contains what appears to be an ISO-9660 filesystem. However, if you have a rip of the track and try to mount the image with standard tools, it will not work. In the second layout, the data follows no obvious format.

  Cracking The Filesystem Code
  I figured out quite a few years ago that in the case of the consolidated data track 3, that’s simply a standard ISO-9660 filesystem that would work fine with standard ISO-9660 reading software… if the data track were located beginning at sector 45000. The filesystem data structures contain references to absolute sector numbers. Thus, if it were possible to modify some ISO-9660 software to assume the first sector is 45000, it ought to have no trouble interpreting the data.

  
  
  

  How about the split data track format ? Actually, it works the same way. If all the data were sitting on its original disc, track 3 would have data structures pointing to strings of contiguous sectors (extents) in the final track, and those are the files.

  To express more succinctly : track 3 contains the filesystem root structure and the directory structures, while the final track contains the actual file data. How is the filesystem always 100% full ? Track 3 gets padded out with 0-sectors until the beginning of any audio sectors.

  
  
  

  Why Lay Things Out Like This ?
  Why push the data as far out on the disc as possible ? A reasonable explanation for this would be for read performance. Compact discs operate on Constant Linear Velocity (CLV), vs. Constant Angular Velocity (CAV). The implication of this is that data on the outside of the disc is read faster than data on the inside. I once profiled this characteristic in order to prove it to myself, using both PC CD drives as well as a Dreamcast. By pushing the data to the outer sectors, graphical data gets loaded into RAM faster, and full motion videos, which require a certain minimum bitrate for a good experience, have a better guarantee that playback will be smooth.

  Implications For Repacking
  Once people figured out how to boot burned CDs in the Dreamcast, they had a new problem : Squeeze as much as 1 gigabyte down to around 650 megabytes at the most. It looks like the most straightforward strategy was to simply rework the filesystem to remove the often enormous amount of empty space in track 3.

  My understanding is that another major strategy is to re-encode certain large assets. Full motion video (FMV) assets are a good target here since the prevailing FMV middleware format used on Sega Dreamcast games was Sofdec, which is basically just MPEG-1 video. There is ample opportunity to transcode these files to lower bitrate settings to squeeze some bits (and a lot of visual quality) out of them.

  Further, if you don’t really care about the audio tracks, you could just replace them with brief spurts of silence.

  Making A Tool
  So I could make a tool that would process these collections of files representing a disc. I could also adapt it for various forms that a Dreamcast rip might take (I have found at least 3 so far). I could eventually expand it to handle lots of other disc formats (you know, something like Aaru does these days). And that would have been my modus operandi perhaps 10 or more years ago. And of course, the ambitious tool would have never seen daylight as I got distracted by other ideas.

  I wanted to get a solution up and running as quickly as possible this time. Here was my initial brainstorm : assemble all the tracks into a single, large disc while pretending the audio tracks consist of 2048-byte sectors. In doing so, I ought to be able to use fuseiso to mount the giant image, with a modification to look for the starting sector at a somewhat nonstandard location.

  To achieve the first part I wrote a quick Python script that processed the contents of a GDI file, which was stored alongside the ISO (data) and RAW (audio) track track rips from when I extracted the disc. The GDI is a very matter-of-fact listing of the tracks and their properties, e.g. :

  5
  1 0 4 2048 track01.iso 0
  2 721 0 2352 track02.raw 0
  3 45000 4 2048 track03.iso 0
  4 338449 0 2352 track04.raw 0
  5 349096 4 2048 track05.iso 0
  

  track number / starting sector / track type (4=data, 0=audio) / bytes per sector / filename / ??

  The script skips the first 2 filenames, instead writing 45000 zero sectors in order to simulate the CD-compatible area. Then, for each file, if it’s an ISO, append the data to the final data file ; if it’s audio, compute the number of sectors occupied, and then append that number of 2048-byte zero sectors to the final data file.

  Finally, to interpret the filesystem, I used an old tool that I’ve relied upon for a long time– fuseiso. This is a program that leverages Filesystem in Userspace (FUSE) to mount ISO-9660 filesystems as part of the local filesystem, without needing root privileges. The original source hasn’t been updated for 15 years, but I found a repo that attempts to modernize it slightly. I forked a version which fixes a few build issues.

  Anyway, I just had to update a table to ask it to start looking for the root ISO-9660 filesystem at a different location than normal. Suddenly, after so many years, I was able to freely browse a GD-ROM filesystem directly under Linux !

  Conclusion And Next Steps
  I had to hack the fuseiso3 tool a bit in order to make this work. I don’t think it’s especially valuable to make sure anyone can run with the same modifications since the tool assumes that a GD-ROM rip has been processed through the exact pipeline I described above.

  I have uploaded all of the North American Dreamcast demo discs to archive.org. See this post for a more granular breakdown of what this entails. In the course of this exercise, I also found some European demo discs that could use the same extraction.

  What else ? Should I perform the same extraction experiment for all known Dreamcast games ? Would anyone care ? Maybe if there’s a demand for it.

  Here is a followup on the interesting and weird things I have found on these discs so far.

  The post Understanding The Dreamcast GD-ROM Layout first appeared on Breaking Eggs And Making Omelettes.